import java.util.*;

public class Test1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        HashSet<Character> hashSet = new HashSet<>() ;
        Queue<Integer> queue = new LinkedList<>();
        Stack<Integer> stack = new Stack<>() ;
        boolean flg = true ;
        while (flg){

        }
        StringBuilder stringBuilder = new StringBuilder() ;
        stack.empty();
    }
}
